Apparatus for determining pupil dimensions

Abstract

A binocular apparatus for determining pupil dimensions for the eyes of a subject which include an optical imaging apparatus permitting images defining each pupil to be simultaneously transmitted along separate optical paths to a common optical sensing device. The binocular apparatus is useful in measuring anisocoria and in detecting drug abuse and/or opiate addiction. A method for determining pupil dimensions for the eyes is also presented.

We claim: 
     
       1. Binocular apparatus for determining pupil dimensions for the eyes of a subject, said apparatus comprising optical imaging means whereby in use images defining each respective pupil are simultaneously transmitted along separate optical paths onto separate areas of a common optical sensing means, said apparatus further comprising a divider positioned between said separate optical paths and closely adjacent to said optical sensing means so as to enhance optical separation of said areas and the optical paths leading thereto. 
     
     
       2. Apparatus as claimed in claim 1 wherein the optical sensing means comprises a two-dimensional array of charge-coupled devices. 
     
     
       3. Apparatus as claimed in claim 2 including means for irradiating each eye with infra-red radiation whereby in use infra-red images defining the respective pupils are focused substantially at said array of charge-coupled devices. 
     
     
       4. Apparatus as claimed in claim 3 wherein said irradiating means comprise infra-red emitting diodes. 
     
     
       5. The apparatus as claimed in claim 2 wherein the optical sensing means includes a CCD video camera. 
     
     
       6. The apparatus as claimed in claim 5 further comprising a video tape recorder including a video tape whereby the tape can be processed at a site remote from the recording site. 
     
     
       7. Apparatus as claimed in claim 1 wherein the optical sensing means comprises a photographic film. 
     
     
       8. Apparatus as claimed in claim 7 including electronic flashgun means having optical fibers leading therefrom such that in use each eye is irradiated. 
     
     
       9. Apparatus as claimed in claim 8 including shutter means interrupting the two optical paths and having an operating mechanism linked to switching means for said flashgun means whereby the flashgun means are triggered when said shutter means are opened. 
     
     
       10. Apparatus as claimed in claim 1 including means for illuminating each eye with a controlled and uniform amount of visible light so as in use to provide an ambient illumination level. 
     
     
       11. Apparatus as claimed in claim 1 including means whereby the apparatus is adaptable to the interpupillary distances of individual subjects while maintaining a constant optical path length. 
     
     
       12. Apparatus as claimed in claim 11 wherein said adjusting means comprise periscopic eyepieces mounted so as to be axially moveable about each optical path. 
     
     
       13. The apparatus as claimed in claim 1 further including a computerized image processing means to afford automatic determination of the pupil dimensions. 
     
     
       14. Apparatus as claimed in claim 1 wherein said divider comprises a divider plate extending perpendicularly from a position closely adjacent to said optical sensing means. 
     
     
       15. A method for determining pupil dimensions for the eyes of a subject comprising simultaneously projecting and separating images defining each respective pupil along separate optical paths onto separate areas of a common optical sensing means. 
     
     
       16. A method as claimed in claim 15 wherein the output from the optical sensing means is subjected to computerized image processing to afford automatic determination of the pupil dimensions. 
     
     
       17. A method as claimed in claim 16 wherein the computerized image processing includes a circle-fitting algorithm. 
     
     
       18. A method as claimed in claim 17 wherein the output from the optical sensing means is recorded on video tape for processing at a site remote from the recording site. 
     
     
       19. A method as claimed in claim 16 wherein the output from the optical sensing means is recorded on video tape for processing at a site remote from the recording site. 
     
     
       20. A method as claimed in claim 15 wherein the images from the optical sensing means are placed on a photographic film. 
     
     
       21. A method as claimed in claim 20 wherein the resulting photographic images are subsequently analyzed digitally. 
     
     
       22. A method as claimed in claim 15 including the detection of drug abuse. 
     
     
       23. A method as claimed in claim 22 including the detection of opiate addiction. 
     
     
       24. A method as claimed in claim 23 wherein the opiate addiction includes a Naloxone eye-drop test.